I was benchmarking the VM late last night and checking startup time and again noticed we invoke flushExternalPrimitives to scan over all object memory
Interpreter>>flushExternalPrimitives
"Flush the references to external functions from plugin primitives. This will force a reload of those primitives when accessed next. "
On August 6, 2003 I had written a note "[ENH][VM] faster image startup" about this and had a change set to reset only the method contexts that we had noticed needed being reset in an earlier scan of memory when we were either adjusting t the oops offset or to address intel/powerpc issues.
However the comments in initialCleanup imply we only should do this for earlier VM, not 3.8 or perhaps 3.6/3.7 I recall some discussion about changes to image saving so that new images wouldn't have this problem and then not require the scan. So did that fix get lost somewhere, or was an issue found and we should again look at how many times we scan oops memory at startup time?
initialCleanup "Images written by VMs earlier than 3.6/3.7 will wrongly have the root bit set on the active context. Besides clearing the root bit, we treat this as a marker that these images also lack a cleanup of external primitives (which has been introduced at the same time when the root bit problem was fixed). In this case, we merely flush them from here."
((self longAt: activeContext) bitAnd: RootBit) = 0 ifTrue: [^nil]. "root bit is clean" "Clean root bit of activeContext" self longAt: activeContext put: ((self longAt: activeContext) bitAnd: AllButRootBit). "Clean external primitives" self flushExternalPrimitives.
-- ======================================================================== === John M. McIntosh johnmci@smalltalkconsulting.com 1-800-477-2659 Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com ======================================================================== ===